Ford Sierra cars are scarce on the roads these days because technology and expectations have moved on, and there’s a relatively fast turnover in Britain’s car fleet. In fact, cars, buses and trucks from the 1970s and 1980s are classic collectables, as a visit to a vintage vehicle rally will confirm. However, on Britain’s rail network, diesel trains of such antiquity are still in frontline service – and will remain so for at least a decade to come. Some locomotives, saved from the cutting torch by nostalgic enthusiasts, have returned to the rail network to plug gaps in the diesel fleet.
Passenger trains aren’t immune to changes in public expectations but have a design life of about 30 years. By 2020, the rail industry must retrofit thousands of passenger vehicles to meet accessibility requirements known as PRM-TSI (persons of reduced mobility technical specification for interoperability). Ensuring vehicles remain reliable beyond their design life also requires interventions.
The root of these challenges is Britain’s patchwork approach to electrifying railways. Even some of London’s commuter routes are still worked by diesels. In 2007, the Department for Transport said, in the white paper Delivering a Sustainable Railway, “It would not be prudent to commit now to ‘all-or-nothing’ projects, such as network-wide electrification or a high-speed line, for which the longer-term benefits are currently uncertain and which could delay tackling the current strategic priorities such as capacity.”
The DfT changed its mind in 2009 and now espouses extensive electrification. Orders for new diesel passenger trains have ended, partly because of the difficulties of complying with the EU’s latest emissions standards within the constrained British loading gauge – the maximum cross-sectional profile. In addition, spreading electrification makes future demand for diesel trains too opaque for the financial institutions involved.
Introducing electric trains to extra routes should displace some of the oldest diesel units for scrap. However, rail passenger numbers have grown, so most diesel units displaced over the next few years will be needed on non-electrified routes to meet existing or latent demand, and for new services.
At Northern Rail, the average age of the trains exceeds 24 years, and 87% of the fleet operates on diesel. Companies bidding for the next Northern franchise will need to outline how they would enable complete withdrawal of Pacer units – diesel trains that were developed from bus technology during straitened times for British Rail in the early 1980s. Each vehicle has a rigid two-axle chassis – instead of the usual four axles, held in pivoted bogies – which makes for a bumpy ride and can cause the wheels to screech on sharply curved track.
Pacers account for one in three of Northern’s trains, and are also used by Arriva Trains Wales and First Great Western. The industry had presumed that they would be scrapped by 2020, but Northern’s passenger numbers have grown by 66% over 10 years. Rolling stock engineers have devised ways to make Pacers compliant with PRM-TSI, because new electrification is likely to be too slow and passenger growth too rapid for all Pacers to be withdrawn by 2020. Sprinter units, also from the 1980s, need similar modifications to comply with current standards for ease of use by people with impaired vision, hearing or mobility.
One demand is that each train should have at least one toilet that can accommodate a wheelchair by 2020. A suitable compliant unit has been developed by composite manufacturer PCC.eu. The first of its toilets were installed in trains last year, and now the South Wales company has orders for almost 1,000 more.
A key benefit of the new toilets is reduced water consumption. “The first thing people do when they go into a train toilet is flush,” says Mark Isaac, managing director of PCC.eu. “An old-fashioned toilet will use nine litres of water.” Passengers entering the new toilets are invited to initiate a preliminary flush which consumes 0.15 litres of water. The full flush uses only 0.4 litres. One of the roof-mounted water tanks can therefore be removed and the weight saving used to fit a retention tank beneath the vehicle. This measure stops raw sewage being flushed onto the tracks – a hazard for people who work trackside.
The smaller retention tank required increases the chances that space can be found for it beneath the floor. PCC.eu is developing a carbon composite tank, for further weight savings over the usual steel.
The toilet on each Pacer unit should be accessible from more than one wheelchair space. To avoid a signifcant reduction in seating at one end of the train – with a toilet and two wheelchair spaces in close proximity – engineers have suggested placing the second wheelchair space in the adjacent carriage. However, the inter-carriage gangway connection would have to be widened for wheelchairs to fit through – an expensive adaptation for low-quality trains. So the industry may seek alternatives, such as making some Pacer units toilet-less trains that are restricted to short routes, or derogations for non-compliant vehicles to continue for a period after 1 January 2020.
Seventies star: The InterCity 125 service included the Flying Scotsman
Another train that will remain in use long after the routes where it runs are electrified is the diesel-powered InterCity 125, used on the Great Western and Midland main lines. The new Great Western electric fleet by Hitachi will include hybrid units, with diesel engines for operation beyond the extremities of electrification, but not in sufficient quantity to cover all services over the non-electrified tracks west of Newbury, Oxford and Bristol.
Some characteristics are being updated on the InterCity 125. Its existing manual door design requires passengers to reach through a window to operate the external handle without leaning on the door – a manoeuvre that can cost train operators precious seconds during stops. In addition, passengers often leave windows open, forcing the heating and air conditioning to work harder. So power-operated doors, or internal door handles, will be required to continue in service after 2019. Powered plug doors have been provided for the same type of vehicle on Chiltern Railways by Rail Door Solutions of Milton Keynes.
Another aspect to be updated is the engines. The Paxman Valenta engines fitted to the InterCity 125s in the 1970s have been replaced over the past 10 years. Leasing company Porterbrook expects to find new leases for InterCity 125s displaced by Great Western electrification when the replacement engines from MTU of Germany “will not even have reached half of their predicted service life”.
The veteran diesels have good and bad points. The engineers who manage day-to-day fleet maintenance say that the ex-British Rail diesel trains have the advantage of mechanical simplicity over newer diesel units, with their relatively complex electronics. Pacer and Sprinter units even lack air conditioning. However, the older units are more prone to failures while in service, notwithstanding decades of modifications.
The powered doors on Pacer units, of the folding type favoured by bus manufacturers, were a significant cause of unreliability for Arriva Trains Wales (ATW) until it commissioned Train Door Solutions, also of Milton Keynes, to install new door-control equipment and overhaul the door systems. This improvement took train doors out of the top five causes of unreliability on the Pacers.
Another area where problems have occurred is signalling. Matt Prosser, head of engineering at ATW, recalls “fundamental issues” with marrying modern equipment and software to trains designed in the late 1980s. Doppler radar, odometers and equipment to communicate with trackside balises were required on the trains. Now ATW, with Network Rail and Ansaldo, has implemented the UK’s pilot of the European rail traffic management system (ERTMS), which replaces conventional signalling with near-continuous communication between each train and a central computer.
The driver-machine interface – the screen that conveys control and safety information to the driver – had to be shoehorned into the small cabs of the diesel units that ATW uses in Mid Wales. Drivers were trained on a simulator inside a building, and it was not until test runs on the railway coincided with sunshine that glare was found to obscure the driver’s view of the screen. Solutions included fitting a blind and tinted glass to the side window, and drivers wearing dark instead of white shirts.
Pacer and Sprinter units may be dwindling by the time ERTMS reaches other secondary routes, as the roll-out is prioritising main lines. Given the experience from the pilot, train operators and owners may be wary of fitting other new software to ageing diesel units. Knorr-Bremse’s Leader driver advisory system, for example, has been fitted to many diesel trains built in the past 15 years. It informs drivers of the most fuel-efficient way to drive, taking account of the route’s topography, timetables and the train’s position and dynamics. Knorr-Bremse is confident Leader “can be installed onto all passenger and freight trains in the UK”.
Equipping old diesel trains for continued service presents opportunities for many businesses, including new entrants to the rail industry. Whereas British orders for new trains involve international supply chains or importing completed vehicles, refurbishing and modernising old rolling stock is a domestic activity. Knorr-Bremse employs more than 200 people at its RailServices sites in Glasgow and Milton Keynes. The sites can undertake whole train and systems refurbishment projects, including wheel and bogie overhaul. The firm gained experience of PRM-TSI compliance in 2012 and 2013, during refurbishment of a group of Greater Anglia Sprinter units.
Another company gaining experience on Sprinters is Arriva-owned LNWR, in Crewe, which last December discovered corrosion on one of these units. With the overhaul of many more units pending, engineers paused the programme while they refined processes to maximise efficiency in tackling corrosion repairs.
Where possible, modifications are programmed to coincide with regular overhauls, to reduce the time each unit is out of service. Deferring work, and creating a backlog that has to be cleared in a rush before 2020, would increase the cost.
Usually, rolling-stock owners determine the scope and timing of modifications in conjunction with medium-term lessors, in the shape of rail franchise holders. But the government’s programme of awarding new rail franchises was frozen after the West Coast franchise competition was abandoned in 2012, and has been slow to thaw. Consequently, leases on many vehicles end within the next few years and holders of short, caretaker franchises have no reason or remit to plan maintenance and modification beyond their tenure.
The effect of this short-term outlook is transmitted along the supply chain, says Rupert Brennan-Brown of the Derby and Derbyshire Rail Forum. “The government looks like it has begun to recognise the challenges,” he says. “To encourage innovation and ensure a competitive supply chain, there needs to be long-term certainty on the work bank for upgrade and modification of Britain’s rolling stock.”
Key freight role
Rail freight relies even more heavily than the passenger sector on diesel. Electrification schemes usually follow passenger corridors, leaving most freight runs with discontinuous electrification. Just 1km without electricity supply in a 400km haul would enforce diesel haulage for at least part of the way, and the practicalities of swapping locomotives en route result in a lot of freight being diesel-hauled ‘under the wires’.
One operator, Direct Rail Services, has ordered 10 electro-diesel locomotives from Vossloh, to use electricity where available and a 700kW Caterpillar diesel engine elsewhere. British Rail had the same idea in the 1960s, and now Rail Vehicle Engineering of Derby is rebuilding veteran electro-diesels for 1,100kW in diesel mode, compared with 480kW as built.
Some operators have bought new diesel locomotives to comply with tougher emissions limits. But compliance could add 50% to the price of a new locomotive, so there is a focus on rehabilitating ex-British Rail diesels. Balfour Beatty recently applied its logo to diesels of a type introduced in 1957. Another vehicle hauling freight is a Deltic locomotive, whose configuration evolved from the diesel technology of Hitler’s Germany.